Hearing devices are wearable hearing apparatuses used to assist those with impaired hearing. To meet the numerous individual requirements different designs of hearing device are available, such as behind-the-ear hearing devices (BTE), hearing devices with an external earpiece (RIC: receiver in the canal) and in-the-ear hearing devices (ITE), e.g. also concha hearing devices or canal hearing devices (CIC). The hearing devices mentioned by way of example are worn on the outer ear or in the auditory canal. In addition to these designs however there are also bone conduction hearing aids, implantable or vibro-tactile hearing aids available on the market. With these the damaged hearing is stimulated either mechanically or electrically.
Hearing devices principally have as their main components an input converter, an amplifier and an output converter. The input converter is as a rule a sound receiver, e.g. a microphone, and/or an electromagnetic receiver, e.g. an induction coil. The output converter is mostly implemented as an electroacoustic converter, e.g. a miniature loudspeaker, or as an electromechanical converter, e.g. a bone conduction earpiece. The amplifier is usually integrated into a signal processing unit. This basic structure is shown in FIG. 1, using a behind the ear hearing device 1 as an example. One or more microphones 2 for receiving the sound from the surroundings is/are built into a hearing device housing 1 to be worn behind the ear. A signal processing unit 3 which is also integrated into the hearing device housing 1 processes the microphone signals and amplifies them. The output signal of the signal processing unit 3 is transmitted to a loudspeaker or earpiece 4 which outputs an acoustic signal. The sound is optionally transmitted by way of a sound tube, which is fixed with an otoplastic in the auditory canal, to the hearing device wearer's eardrum. The power is supplied to the hearing device and especially to the signal processing unit 3 by a battery 5 also integrated into the hearing device housing 1.